What am I seeing?

So the other day I did my final inspection and started preparing the hive for winter. A few minutes after I had finished I noticed I put my feeder rim on upside down. I re opened the hive and saw that the bees had clustered on the inner cover..looked almost like a swarm cluster, bees clinging to each other etc..
I knocked them down (gently) and re checked again a day or two later. Still had a cluster but this time it was a baseball sized cluster. Can any one tell me what this behavior is? I am a first year beekeeper up in Maine..

I would not get them out of cluster for they are probity covering the brood in the hive for it may be to cool them and you could cause them to lose some baby bees, I would never disturb a cluster in the hive. Oh and welcome to the forum.

Move the clump from the inner cover into a nuc with a couple of frames of brood and food and see what they do. That i what I would do. Put the nuc in a garage or shed or between established hives for a windblock and plug it up so they stay inside and don't go out and freeze, check in 2 days? Now, I am in Texas and about to move a big hive down into a stacked nuc. But I am in Texas. It could freeze here within 2 weeks but probably 3 to 4. When you do open it, if you do, use a really small entrance reducer to prevent robbing and to keep them in, If you find freshly laid brood when you check on it, consider making them an observation hive this winter

I would not move them to a nuc with winter coming in Maine. Never mind if there is a queen in the cluster. With you making some changes to the upper top of the hive they may be gathering to propolus it up to do there own winterizing. Don't worry if multi queen......I read that they estimate almost 80% of the colonies un-manned are multi-queened. Make sure they have enough higher ventilation, or they will have too much condensation!

If that doesn't pacify you, just switch inner covers to a different one......you will be taking that cluster pherimone away from them. Just be sure to give them a used one with plenty of propolus on it for winter!

Thanks for all the advice everyone! I talked with my bee guy up here and he said that they should move down on their own. I opened the top to take a picture and saw that they had made a small amount of comb..which I removed. I am feeding them and they are still taking in a feeder full (entrance) a day. I'm hoping when they stop feeding they will go back down.

Not really sure but believe that in this northern climate bees won't build on the lower part of the frames and it seems to reduce brood area for me. I tried a few. I also had lower winter survival with them. I use solid bottom boards exclusively now. But others in my area still use them. I saw no advantage in mite counts with them either, which was the impetus for me to try them.

I had an unusually cold winter last year and did not get sticky boards into my screened bottom boards early enough, I believe it did not help my hives to get that cold. BUT my hive stands are 18 inches off the ground and not solid, they are pipe stands so the wind really can ventilate in the heat, but also in the winter. I have sticky boards in now for mite counts during OA treatment, and I will be putting slightly ventilated sticky boards in for the winter, to help prevent moisture buildup without chilling the bees. I think the best winter I have had that is what I did

My last 2 winters were pretty harsh (below -20*F), I had a screened hive bottom and a gap between hive bodies. Both times my hive came through the winter, although the first winter they barely made it (more days -20*F). I'm now a firm believer in ventilating.

I have left my screen bottom board on. My hive is up on cinder blocks, I put hay bales around the base and cinder blocks to break the wind..I'm hoping this works. This is my first year with a hive and so far has gone pretty well other than the fact that the bees have clustered up on the inner cover. The second deep is full of honey so if they go back down they should have enough to get through the winter.